1. Field of the Disclosure
The present application relates to an organic light-emitting display (OLED) device.
2. Description of the Related Art
Display devices for displaying information are being widely developed. The display devices include liquid crystal display devices, organic light-emitting display devices, electrophoresis display devices, field emission display devices, and plasma display device.
Among these display devices, organic light-emitting display devices have the features of lower power consumption, wider viewing angle, lighter weight and higher brightness compared to liquid crystal display devices. As such, the organic light-emitting display device (OLED) is considered to be a next generation display device.
Thin film transistors used in the organic light-emitting display device can be driven in high speed. To this end, the thin film transistors increase carrier mobility using a semiconductor layer which is formed from polysilicon. Polysilicon can be derived from amorphous silicon through a crystallizing process.
A laser scanning mode is widely used in the crystallizing process. During such a crystallizing process, the power of a laser beam may be unstable. As such, the thin film transistors formed along the scanned line, which is scanned by the laser beam, can have different threshold voltages from each other due to different mobilities in each thin film transistor. This can cause image quality to be non-uniform between pixels.
To address this matter, a technology detecting the threshold voltages of pixels and compensating for the threshold voltages of thin film transistors had been proposed. However, in order to realize such threshold voltage compensation, transistors and signal lines connected between the transistors must be added into the pixel. Addition of such transistors and signal lines increases the circuit configuration of the pixel. Moreover, the added transistor and signal lines can reduce an aperture ratio of the pixel, which causes shortening of the life span of the OLED device.